Sound-conveying means for talking machines



" April 22, 1924; ma s o w. 1.. ECKHARDT v SOUND CONVEYING MEANS FOR TALKING MACHINES Filed De 8, 1920 INVEVNTOR.

A TTORNE Y.

Patented Apr. 22, 1924.

"UNITED STATES WALTER L. O! PHILADELPHIA, PENNSYLVANIA.

SOUND-CONVEYING MEANS FOR TAI KING MACHINES.

Application filed December 8, 1980. Serial K0. 89,086.

To all whom it may concern:

Be it known that I, WALTER L. Ecxnann r,

a citizen of the United States, and a resident of Philadel hia, in the county of Philadelphia and dtate of Pennsylvania, have mvented an Improvement in Sound-Conveying Means for Talking Machines, of which the following is a specification.

My invention relates to sound conveying means for talking machines, and it has for one of its objects to provide means whereby the re reduced talking and musical tones are richer and more p easi to the ear of the listener than such tones eretofore have been; that is, b the employment of my invention the qua 'ty of there roduced sounds, both vocal and instrumenta is improved.

It is also an object of myeinvention to provide means adapted to associated and combined with the ordinary sound conveying or tone-arm of a talking machine to effect an improvement in the tone and quahtg of the sounds, vocal and instrumental, whic may be reproduced thereby.

A further object ofrm invention is to provide means whereby a ody or reservoir of fluid, such as air, may be contained in surrounding or enveloping relation with respect to the sides of a sound conveying or tone-arm of a talking machine. It is believed by me that one reason why the pres ence of an air-tight or practically air-tight chamber filled with a fluid, such as air, surrounding the sides of a sound conveying or tone arm of a talking machine causes an improvement in the quality of regoduced sounds is that such presence more e ectively confines the sound wave vibrations within the said arm; that is, prevents or diminishes d6 full efiect of the sound waves producedhy and emanating from the diaphragm of the sound box is transmitted to the am lifier proper of the machine. It is also be 'eved that the presence of such air tight air or filled chamber surrounding the sidfw of the arm shields the sound producing vihratio within the sound conveying or tone arm against extraneous disturbin influences and thereb permits and causes elivery thereof from t e said arm to the amplifier of the machine in a more natural condition; that is, the form and condition thereof, except as dissipation thereof, whereby more nearly the amplified, as originally produced and initiated by the diaphragm of the sound box.] Although it is believed that the foregoing .essential thing is that the employment of the novel means embodying my invention accomgllishes an important new result.

A rther object of my invention is to provide an improvement in the, means for connecting'the sound conveying arm or tone arm to the top of the cabinet or casing of the machine or to a stationary member or element secured to such top.

Other olflects and advantages of my invention wi be pointed out in the detailed description thereof which; follows or will be apparent from such description.

In order that my invention. may be easily understood and its practical advant y appreciated, reference should be ha 0 to the accom anying drawing in which one form of em odiment of my invention is shown. It will is understood however that changes in the details of construction may be made within the sec of the claims without departing from t e said invention.

In the dra 1.

Fig. 1 is a view in central vertical section of portions of the up r part of a talking machine provided w1t a sound conveying arm or tone arm provided with my invention; I

Fig. 2 is a top plan view thereof; and

Fig. 3 is a view in vertical section oi utions of the said am showing in detail ow it is pivotally' secured to a tubular bracket which is in turn stationarily secured to the oi the cabinet or casing of the machine.

"i -11s t0 the d 1 the sides a cabinet which may y hno construction and 2 the top thereof, to t% under side of which the motor 8 is escured. The turn table 5 for supporti the records, one of which is shown at 6, s ascured to the -u per end of the motor shaft 7 and rotates t erewith in the usual mer. The stylus 10 for enga the race 6 o eenne'etion with we e501 2I d x 11w 'chllatter may be of any known construction? The sound box is rovided with a rearway'extending tuber proj ection 12, the rear end of which termina in a spherical portiones shown at 13 wch is in pivotal ewwith the interior of a like spheriea wrtion 1d at the forward end of the tubii'lar wund 'eying arm .or tonearm comprising arts or sections 15 and 17. The spherical portions 13 and 1d are provided with additional connections consisting of horizontally ivots 16 about which the sound box may wmoved to pivotally. V

' w m: portion'of the part, 15 of the 7 tone-arm extends suntially at right anglw to the aining front portion thereof d is provided at its rear end with an in l. threade expandedportion 18 wi is the upper end of the part 17, the lower end of ,hich is he or filled, as shown. The lower dared d of the part 17 termina within the as end portion of an am'lifier or horn distance below e upper end The said horn may be of any hows. construction.

' By extending the rear end of the tonearm into the upper end portion of the amplifier or born 18 as shown, all of the sound vibrations transmitted tlu'ou h the said a are delivered-to the horn wit out loss, to be orded. The dimipation of the sound vibrations at this int is avoided by my construction in which the r end of the tone-arm exds into the gm end portion of the plifier or he 1.

The air ti 3 t aim previously referred to which surrounds the sides of the tone arm 15 is feed 3 means of an inclosin casi hi) which,;in construction shown, is of tapering to all tion but may be of an other shape. The thing. is that it shall incloee th sides to to a chamber surrounding the said tone-arm. At its forward will the "as:

This connection may be efiiected by brazing, deri or in any at "-7. way which may m ired and-found to be ractical. As in the a: of e tone=arm h mar end portion of the casing ends as tially at right angles to the remainin front portion thereof. its rear ends of t part 15 of the tonearm aid wsi 20 termin in pradically the e lane and are connected or secured together mns of an aular plug 21 which is sihiated in the co Mtween the of id new; 20 and the exinane of the sound vibrations would is connected to the tone-arm.

The rear ends of'the ended rtion 16 of the part 15. The pl 1 is secured to the rear ends of the part 15 aud t-be casing 20 and seals the chamber surroundin the said part 15 formed by the casing 20. hebottom side of said plug is hush with the adjacent edge of the parts 15 and 20. r

flhe edges of the rear ends of the part 15 of the tone-arm and casing 20 and the outer rear side of the. lug 2,1 (which also may be 'regarded as a aring means) rest upon the upper; side of an inwardly extendm flange 22 upon a tubularibracket 23 secure to the upper side of the top 2 of; the cabinet.

part 15 of the tonearm and casing are retained in position 11 n the flange 22 by means ofa flange-like co lar 24 secured to the part 17 of the tone-arm near the end thereof which is secured to the rear end of the part 15. There should be slight play between the collar 24 and the flange 22,-just suflicient topermit free pivotal or rotary movement of the tone-arm and easing abouta vertical axis upon the said flange so as to permit lateral swingin movements of the tone-arm, casing, soun box and stylus over the record 6.

It will be seen that in addition to providing means whereby the quality of the repro= duced sounds, vocal or instrumental, is improved, l have also provided means whereby the tone-arm may be readily and easily connected with and disconnected from the tubular bracket 23. The assembling of these parts and the connection thereof to the to 2 ofd the cabinet are thereby greatly facilitate Having thus described my invention, what I claim and dire to secure by Letters Patent, 1s:

1. in combination, a tubular tone-arm for a talking machine oom rising front and rear parts, t 9 front part ing of uniform diameter and having an expanded portion at its rear end, and the said rear part havin detachable connection with said expand portion, a bearing means provided upon the outer side of said expanded portion, the lower side of which is flush with the adjacent ed of the said expanded portion, an annular support for the said bearing means, and means provided gm the said rear part of the tone-arm and situated practically in contact with the lower side of the said annular gr-I and cooperating with the said bearing 5 or conneming the tone arm to the said annular support.

2. in combination, a tubular tone 8., a casing inclosing the sides'of the tone arm from a point adjacent its front end to a point near its rear end and being spaced therefrom to form a chamber surrounding the same, an annular member situated in the annular space between the rear d of the lid 1,ae1,ceo a 8 said casing and the adjacent portion of the adjacent the'flange of said bracket in opsaid arm, the said annular member being seposed relation to the rear end of the said 10 cured to the said casing and to the adjacent casing and to the said annular member. portion of the said arm, a bracket having In testimony that I claim the foregoing an inwardly extending flange upon which as my invention I have hereunto set m the said annular member is supported, and a name this 29th day of November, A. D. 1920. collar secured to the rear part of the said tone arm which collar occupies a position I WALTER L. EGKHARDT. 

